Radioactivity of neutron deficient isotopes in the region<i>N</i>&gt;82&gt;<i>Z</i>

The \ensuremath{\alpha} decay characteristics of 88 decay lines emanating from 74 isotopes are presented, including new \ensuremath{\alpha} decay lines identified in the neutron deficient nuclides $^{158}\mathrm{Ta}$ (${\mathit{E}}_{\mathrm{\ensuremath{\alpha}}}$=5969\ifmmode\pm\else\textpm\fi{}8 keV, ${\mathit{t}}_{1/2}$=46\ifmmode\pm\else\textpm\fi{}4 ms), $^{159}\mathrm{Ta}$ (${\mathit{E}}_{\mathrm{\ensuremath{\alpha}}}$=5516\ifmmode\pm\else\textpm\fi{}5 keV, ${\mathit{t}}_{1/2}$=1100\ifmmode\pm\else\textpm\fi{}100 ms), $^{160}\mathrm{Ta}$ (${\mathit{E}}_{\mathrm{\ensuremath{\alpha}}}$=5313\ifmmode\pm\else\textpm\fi{}5 keV, ${\mathit{t}}_{1/2}$=1700\ifmmode\pm\else\textpm\fi{}200 ms), $^{168}\mathrm{Ir}$ (${\mathit{E}}_{\mathrm{\ensuremath{\alpha}}}$=6323\ifmmode\pm\else\textpm\fi{}8 keV, ${\mathit{t}}_{1/2}$=161\ifmmode\pm\else\textpm\fi{}21 ms, ${\mathit{b}}_{\mathrm{\ensuremath{\alpha}}}$=82\ifmmode\pm\else\textpm\fi{}14%), and $^{170}\mathrm{Ir}$ (${\mathit{E}}_{\mathrm{\ensuremath{\alpha}}}$=6083\ifmmode\pm\else\textpm\fi{}11 keV, ${\mathit{t}}_{1/2}$=830\ifmmode\pm\else\textpm\fi{}300 ms, ${\mathit{b}}_{\mathrm{\ensuremath{\alpha}}}$=36\ifmmode\pm\else\textpm\fi{}10%). Their correlations with other decay lines are discussed. The alpha decay of a high-spin isomer in $^{157}\mathrm{Ta}$ has been discovered, with an energy of 7744\ifmmode\pm\else\textpm\fi{}8 keV and a half-life of 1.7\ifmmode\pm\else\textpm\fi{}0.1 ms, while the half-life of the corresponding isomeric alpha decay line of $^{158}\mathrm{W}$ has been measured for the first time as 160\ifmmode\pm\else\textpm\fi{}50 \ensuremath{\mu}s. First half-life and branching ratio measurements are also reported for the 5454\ifmmode\pm\else\textpm\fi{}4 keV $^{156}\mathrm{Lu}$ line (${\mathit{t}}_{1/2}$=494\ifmmode\pm\else\textpm\fi{}12 ms), $^{162}\mathrm{Re}$ (${\mathit{b}}_{\mathrm{\ensuremath{\alpha}}}$=85\ifmmode\pm\else\textpm\fi{}9%), $^{163}\mathrm{Os}$ (${\mathit{t}}_{1/2}$=${12}_{\mathrm{\ensuremath{-}}7}^{+11}$ ms), $^{166}\mathrm{Ir}$ (${\mathit{t}}_{1/2}$=12\ifmmode\pm\else\textpm\fi{}1 ms), $^{167}\mathrm{Ir}$ (${\mathit{t}}_{1/2}$=34\ifmmode\pm\else\textpm\fi{}4 ms), the 6227\ifmmode\pm\else\textpm\fi{}15 keV $^{168}\mathrm{Ir}$ line (${\mathit{t}}_{1/2}$=125\ifmmode\pm\else\textpm\fi{}40 ms), and $^{171}\mathrm{Ir}$ (${\mathit{b}}_{\mathrm{\ensuremath{\alpha}}}$=58\ifmmode\pm\else\textpm\fi{}11%). New decay measurements for the proton emitter $^{156}\mathrm{Ta}$ (${\mathit{E}}_{\mathit{p}}$=1108\ifmmode\pm\else\textpm\fi{}8 keV, ${\mathit{t}}_{1/2}$=375\ifmmode\pm\else\textpm\fi{}54 ms, ${\mathit{b}}_{\mathit{p}}$=4.2\ifmmode\pm\else\textpm\fi{}0.9%; ${\mathit{E}}_{\mathit{p}}$=1007\ifmmode\pm\else\textpm\fi{}5 keV, ${\mathit{t}}_{1/2}$=144\ifmmode\pm\else\textpm\fi{}24 ms) are presented. All energies have been measured using a consistent energy calibration procedure for protons and \ensuremath{\alpha} particles. \textcopyright{} 1996 The American Physical Society.

Перевод пока недоступен